Effect of pH condition during sol-gel synthesis on the volume fraction of hydroxyapatite from sea coral

A research Hydroxyapatite synthesis has been carried out using the sol-gel method with variations in acidity (pH). Hydroxyapatite sources are obtained from marine corals from Banyuwangi. Hydroxyapatite synthesis is carried out by reacting calcium hydroxide Ca(OH)₂ obtained from the powder coral with phosphoric acid (H₃PO₄) using the sol-gel method. synthesis is carried out with a pH variation from values 5 to 13 at intervals of 2 and is characterized using XRD (X-Ray Diffractometer). The XRD results show that for hydroxyapatite synthesis using the sol gel method the most optimal pH value is 11 with a volume fraction of 92.7% and the impurities are Lime CaO and Portlandite Ca(OH)₂. (paper)